We are interested in finding out whether or not the nature and relative abundance of carcinogenic hydrocarbon metabolites of cancer patients or of individuals in the precancerous state are different from those of normal healthy individuals and that the alteration is resulted by abnormal functional state of the microsomal enzyme system. By use of two different cell populations, the one selected from high transformation frequency and the other the cells which are relatively resistant to transformation, we are examining any difference in the qualitative and quantitative nature of the hydrocarbon metabolites formed by microsomal enzymes of the two populations of the cells. We are also examining the extent of the metabolites binding to individual chromosomal component such as histone, nonhistone chromosomal proteins, RNA, and DNA. The effects of a variety of factors are studied with respect to relative activity of enzymes and the extent of the binding of the metabolites. Isotope-labeled substrates are used to isolate the metabolites and a highly sensitive, "three-dimensional" fluorescence plotting technique is used for the spectral characterization of the hydrocarbon metabolites.